Lead-off Batter = On-Deck Batter?

[CecilOne]

Originally Posted by Big Slick

In PA, that's our interpretation. As an example, to start the game, the lead off hitter is the only one allowed in the on-deck circle while the home team is warming up. And taking this one step further, if there are no on-deck circles on the field (which is surprisingly all the schools in my county), no one is permitted on the field during warm ups.

Your state association may vary.

The rule does say "single on-deck batter" as quoted; but is this OOO.

However, I think the on deck circle like the batter box and other things exist even if there is no visible line.